Firing a projectile from a firearm often involves the use of a propellant (typically a relatively small volume that is on the order of the volume of the projectile itself) that, upon ignition, explodes into a much larger volume of hot gas. The volume of the hot gas can be as much as 100 times, 1000 times, or more, of the volume of the propellant. Confined by the firing chamber, the volume of hot gas forces the projectile from the firing chamber, through a barrel connected to the firing chamber, and out of the firearm.
The ignition of the propellant not only produces a large volume of hot gas, it also produces a loud sound. Sound suppressors, also known as “silencers,” are configured to reduce the amplitude of the sound waves produced upon ignition of the propellant. Sound suppressors generally attach to a barrel of a firearm and define: (1) an extension of the firearm barrel for the projectile to pass through and (2) a number of channels for the hot gas to pass through. The channels reduce both the temperature of the hot gas and the speed with which the hot gas is travelling. Reducing these in turn reduces the amplitude of the sound resulting from ignition of the propellant.